This invention relates generally to the fabrication of integrated circuits.
As the dimensions of integrated circuits have become smaller and the speed of logic and microprocessor products have increased, a limit is faced after which proceeding in the same fashion will no longer produce the corresponding speed and performance improvements. The RC time constant associated with the interconnects in integrated circuits and the related dielectrics will ultimately slow down the speed improvements achieved by reducing device dimensions.
Thus, interlayer dielectric materials are being developed with decreasing dielectric constants below that of traditional silicon dioxide dielectric. Currently, many such dielectrics are materials that have low mechanical strength as a result of using doped oxides. An example is carbon doped oxide. Dielectric constant materials made from organic materials, such as spin-on dielectric, may also exhibit lower mechanical strength.
The lower mechanical strength of these decreased dielectric constant materials leads to mechanical and structural problems during wafer processing, assembly, and packaging operations. Consequently, there is a need for low dielectric constant materials with good mechanical strength that can withstand wafer processing and assembly operations and so that the resulting products are reliable in operation.
Pure diamond films may be synthesized by various chemical vapor deposition techniques to have very high strength and a low dielectric constant. Diamond films with lower dielectric constants and higher moduluses would be desirable. One approach for reducing the dielectric constants of these films, while still maintaining adequate mechanical properties, is to introduce porosity into the films.
Thus, there is a need for ways to introduce porosity into diamond films used for semiconductor applications.